These are rather odd variations in that the tassies have a slight rounded outward bow of the surface as compared to a traditional flat tassie 75. Samples vary from a narrow cap band sterling silver to the wide band, and even a vermeil version was found. Curiously all were obtained from someone in Israel, so perhaps these are localized for the Middle East.
As you can see, the rounded surface varies quite a bit and in the above three samples the vermeil (C) shows this effect more than the two sterling grids (B and D).
A normal 75 tassie has four stacked rings, but in this comparison between the flat (A) and the vermeil tassies (C), the topmost ring of the vermeil tassie is not as thick as normal. Perhaps this rounded effect is attained by grinding the normal flat tassie on a curved surface instead of being formed that way? If you know, please send me email.